Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
  • B29C45/0013—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor using fillers dispersed in the moulding material, e.g. metal particles
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/20—Compounding polymers with additives, e.g. colouring
  • C08J3/201—Pre-melted polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/20—Compounding polymers with additives, e.g. colouring
  • C08J3/203—Solid polymers with solid and/or liquid additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/54—Silicon-containing compounds
  • C08K5/541—Silicon-containing compounds containing oxygen
  • C08K5/5415—Silicon-containing compounds containing oxygen containing at least one Si—O bond
  • C08K5/5419—Silicon-containing compounds containing oxygen containing at least one Si—O bond containing at least one Si—C bond
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/54—Silicon-containing compounds
  • C08K5/541—Silicon-containing compounds containing oxygen
  • C08K5/5425—Silicon-containing compounds containing oxygen containing at least one C=C bond
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K9/00—Use of pretreated ingredients
  • C08K9/04—Ingredients treated with organic substances
  • C08K9/06—Ingredients treated with organic substances with silicon-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K2201/00—Specific properties of additives
  • C08K2201/011—Nanostructured additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/34—Silicon-containing compounds
  • C08K3/36—Silica

Definitions

• the present disclosure relates to processing aides for extrusion and injection molding.
• nanoparticle including surface-modified nanoparticle, processing aides and the use of such nanoparticle processing aides in extrusion and injection molding processes are described.
• the present disclosure provides a method of processing a mixture in an extruder or injection molder.
• the method comprises melting a solid thermoplastic resin to form a molten resin, melt-mixing the molten resin and surface-modified nanoparticles to form the mixture, and extruding or injection molding the mixture.
• the method further comprises pre-mixing the solid thermoplastic resin and the surface modified nanoparticles prior to melting the solid thermoplastic resin.
• melting the solid thermoplastic resin and melt-mixing the molten resin and the surface modified nanoparticles occur within the extruder or injection molder.
• At least one solid thermoplastic resin comprises a polyester resin, e.g., a polyalkylene terephthalate including those selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate, and polycyclohexylenedimethylene terephthalate.
• at least one solid thermoplastic resin comprises a polyamide, including those selected from the group consisting of polyamide 6, polyamide 66, and polyamide 6/69 copolymer.
• at least one solid thermoplastic resin comprises a polyalkylene, e.g., polyethylene.
• at least one solid thermoplastic resin comprises a liquid crystal polymer, including liquid crystal polymers comprising glass fibers.
• the surface modified nanoparticles comprise silica nanoparticles comprising a silica core and a surface treatment agent covalently bonded to the core.
• at least one surface treatment agent is a trialkoxy alkylsilanes, e.g.,
• At least one surface treatment agent is vinyltrimethoxysilane.
• the mixture comprises 0.5 to 10 wt.%, inclusive, of the surface- modified nanoparticles, e.g., in some embodiments, the mixture comprises 0.5 to 5 wt.%, inclusive, of the surface-modified nanoparticles.
• the present disclosure provides an extruded or injection molded article made according to any one of the methods described herein.
• the above summary of the present disclosure is not intended to describe each embodiment of the present invention.
• the details of one or more embodiments of the invention are also set forth in the description below.
• Other features, objects, and advantages of the invention will be apparent from the description and from the claims.
• melt processing refers to methods of processing a thermoplastic material that involve melting the thermoplastic material.
• Exemplary melt processes include melt-mixing, compounding, extrusion, and injection molding.
• extrusion involves the pushing of a thermoplastic material through a barrel equipped with one or more heated screws that provide a significant amount of shear force and mixing before the material exits the barrel through, e.g., a die.
• the heat and shear forces are generally sufficient to melt some or all of the thermoplastic material early in the extrusion barrel.
• Other additives including fillers may be added along with the thermoplastic material or downstream in the extruder and melt-mixed with the molten thermoplastic material. Forces encountered during extrusion may include radial and tangential deformation stresses, and axial tangential and shear forces during direct the extrusion process.
• injection molding the material to be molded is melted using thermal and shear forces, often in a multi-zone apparatus. As the melted material flows into the mold, a layer forms immediately at walls. The remaining melt fills the rest of the mold with shear forces generated at it flows past the material "frozen” against the mold walls. The maximum shear rate occurs close to the center of the flow. Injection molded materials experience internal stresses occurring from thermal stresses which are compressive near the cavity surface and tensile in the core section. Elastic stresses induced by flow orientation may also present.
• extrusion and injection molding are well-known processes.
• the wide variety of extrusion equipment and injection molders is also well-known. Many variations in the equipment (e.g., screw and die designs) and process conditions (e.g., temperatures and feed rates) have been used. However, there continues to be a need to increase throughput and reduce the forces required to operate extruders and injection molders.
• thermoplastic materials include polyesters (e.g., polyalkylene terephthalates including polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polycyclohexylenedimethylene terephthalate (PCT); and polyethylene naphthalates (PEN) such as 2,6- PEN, 1,4-PEN, 1,5-PEN, 2,7-PEN, and 2,3-PEN,); polyolefins (e.g., polypropylene and polyethylene), polyamides, polyimides, polycarbonates, styrenic polymers and copolymers, and polyacrylates.
• PET polyethylene terephthalate
• PBT polybutylene terephthalate
• PCT polycyclohexylenedimethylene terephthalate
• PEN polyethylene naphthalates
• polyolefins e.g., polypropylene and polyethylene
• polyamides e.g., polyimides, polycarbonates, sty
• Copolymers and mixtures thereof may also be used.
• curable resins may also be used.
• exemplary curable resins include epoxy resins, unsaturated polyester resins, and vinyl ester resins.
• any number of well-known additives may be included in the resin.
• Exemplary additives include dyes, pigments, ultraviolet light stabilizers, mold release agents, tougheners, reinforcing materials, and fillers (e.g., clay, carbon, minerals (e.g., calcium carbonate), and the like).
• fillers e.g., clay, carbon, minerals (e.g., calcium carbonate), and the like.
• glass e.g., glass fibers, shards, spheres, and the like, may be included.
• Other suitable fillers include fibers such as steel, carbon, and/or aramid fibers.
• surface modified nanoparticles comprise surface treatment agents attached to the surface of a core.
• the core is substantially spherical.
• the cores are relatively uniform in primary particle size.
• the cores have a narrow particle size distribution.
• the core is substantially fully condensed.
• the core is amorphous.
• the core is isotropic.
• the core is at least partially crystalline.
• the core is substantially crystalline.
• the particles are substantially non- agglomerated.
• the particles are substantially non-aggregated in contrast to, for example, fumed or pyrogenic silica.
• agglomerated is descriptive of a weak association of primary particles usually held together by charge or polarity. Agglomerated particles can typically be broken down into smaller entities by, for example, shearing forces encountered during dispersion of the agglomerated particles in a liquid.
• aggregated and aggregates are descriptive of a strong association of primary particles often bound together by, for example, residual chemical treatment, covalent chemical bonds, or ionic chemical bonds. Further breakdown of the aggregates into smaller entities is very difficult to achieve. Typically, aggregated particles are not broken down into smaller entities by, for example, shearing forces encountered during dispersion of the aggregated particles in a liquid.
• the nanoparticles comprise silica nanoparticles.
• silica nanoparticle refers to a nanoparticle having a core with a silica surface. This includes nanoparticle cores that are substantially entirely silica, as well nanoparticle cores comprising other inorganic (e.g., metal oxide) or organic cores having a silica surface.
• the core comprises a metal oxide. Any known metal oxide may be used. Exemplary metal oxides include silica, titania, alumina, zirconia, vanadia, chromia, antimony oxide, tin oxide, zinc oxide, ceria, and mixtures thereof.
• the core comprises a non-metal oxide.
• silicas include those available from Nalco Chemical Company, Naperville, Illinois (for example, NALCO 1040, 1042, 1050, 1060, 2326, 2327 and 2329); Nissan Chemical America Company, Houston, Texas (e.g., SNOWTEX-ZL, -OL, -O, -N, -C, -20L, -40, and - 50); and Admatechs Co., Ltd., Japan (for example, SX009-MIE, SX009-MIF, SC1050-MJM, and SC1050-MLV).
• surface treatment agents for silica nanoparticles are organic species having a first functional group capable of covalently chemically attaching to the surface of a nanoparticle, wherein the attached surface treatment agent alters one or more properties of the nanoparticle.
• surface treatment agents have no more than three functional groups for attaching to the core.
• the surface treatment agents have a low molecular weight, e.g. a weight average molecular weight less than 1000 gm/mole.
• the surface-modified nanoparticles are reactive; that is, at least one of the surface treatment agents used to surface modify the nanoparticles of the present disclosure may include a second functional group capable of reacting with one or more of the curable resin(s) and/or one or more of the reactive diluent(s) of the resin system.
• a second functional group capable of reacting with one or more of the curable resin(s) and/or one or more of the reactive diluent(s) of the resin system.
• nanoparticles are reactive, they are not considered to be constituents of the resin component of the resins system.
• Surface treatment agents often include more than one first functional group capable of attaching to the surface of a nanoparticle.
• alkoxy groups are common first functional groups that are capable of reacting with free silanol groups on the surface of a silica nanoparticle forming a covalent bond between the surface treatment agent and the silica surface.
• Examples of surface treatment agents having multiple alkoxy groups include trialkoxy alkylsilanes (e.g.,
• Suitable surface treatment agents include
• the polymer was dried at 82 °C for two hours.
• the dried polymer and varying amounts of nanoparticles were weighed into glass jars to achieve a final total weight of 10 g for each sample, as summarized in Table 2A.
• the jars were shaken to mix the two powders.
• Each sample was loaded into a Micro 15 Twin-Screw extruder (DSM Research Netherlands).
• the extruder was operated at a screw speed of 100 rpm and the mixture was continuously cycled through the extruder to compound surface-modified nanoparticles with a variety of polymers.
• compounding time was set at 2 minutes, as product degradation may occur at longer times in the compounder.
• Tables 3 through 6 summarize the force (N) as a function of time in the compounder (seconds) for various combinations of polymer and nanoparticles.
• Table 3 PET polymer and SMNP-A surface-modified nanoparticles.
• Table 4 PBT polymer and SMNP-A surface-modified nanoparticles.
• Table 6 Nylon-U polymer and SMNP-A surface-modified nanoparticles.
• Polypropylene was compounded in the same manner with 1 wt.% and 2 wt.% SMNP-A surface-modified nanoparticles. This material was then run through the micro-compounder a second time.
• Table 7 summarizes the force (N) versus time in the compounder (seconds) or each sample of polypropylene during the second pass in the compounder. Force reductions of 5 to 14% were obtained at 2 wt.% nanoparticles.
• Table 7 PP polymer and SMNP-A surface-modified nanoparticles.
• Nylon-G polymer was compounded in the same manner with 1 wt.% SMNP-B surface- modified nanoparticles. This material was then run through the micro-compounder a second time. Table 8 summarizes the force (N) versus time in the compounder (seconds) or each sample of Nylon-G during the second pass in the compounder. Force reductions of 15 to 20% were obtained with only 1 wt.% nanoparticles.
• Table 8 Nylon-G polymer and SMNP-B surface-modified nanoparticles.
• Nylon-G N/D 1% (*) 15% 19% 17% 18% 19% 20% N/D not determined; (*) limited data set, Minimum can not be determined.
• Various glass fiber-reinforced polymers suitable for injection molding were combined with SMNP-A surface-modified nanoparticles. Each resin was first dried at the temperature recommended by the manufacturer, as summarized in Table 10. Next, 1000-2000 g of resin was placed in a glass jar and SMNP-A nanoparticles were added to achieve the desired weight percent. The glass jar was sealed, put on rollers, and allowed to tumble for 30 minutes. The mixture was used without further processing in the injection molding trials, conducted using an ARBURG 320C 500-100 55T injection molding machine (Arburg GmbH Lossburg, Germany). For each resin evaluated, the temperatures were set as
• Table 10 Drying and injection molding conditions.
• the resin or resin mixture (nanoparticles plus resin) was placed in the hopper and injection molded into one of two different molds.
• Mold A was a two cavity, standard mold base with a hot sprue and two sub gates.
• Mold B was a single cavity, mud insert base with a cold sprue and two sub gates.
• the pressure needed to reproducibly obtain a completely filled part with a shiny surface was recorded for each of ten shots.
• the average of the minimum injection pressure required was calculated for the ten shots and is reported in Table 1 1.
• Table 1 1 Reduction in injection pressure with a nanoparticle processing aide.

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• 2011
  • 2011-08-31 US US13/825,040 patent/US20130172464A1/en not_active Abandoned
  • 2011-08-31 WO PCT/US2011/049818 patent/WO2012039901A1/en active Application Filing
  • 2011-08-31 CN CN201180045102XA patent/CN103140541A/zh active Pending
  • 2011-08-31 EP EP11758006.8A patent/EP2619254B1/en not_active Not-in-force

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